An extensive body of engraved rock art on the Great Papuan Plateau is documented here for the first time, along with the first dates for occupation. Consisting largely of deeply abraded or pecked barred ovals and cupules, the rock art of this region does not fit comfortably into any regional models for rock art previously described. It does, however, exhibit some similarity to art in regions to the east and the west of the plateau. Subject to further archaeological testing, we present a number of exploratory hypotheses with which to explain the presence of the engravings; as part of the ethnographic and contemporary Kasua's cultural suite; as part of a relatively recent (late Holocene) migration of peoples from the Gulf to the plateau; or as part of an earlier movement of people from the west, possibly as part of the movement of people into the Sahul continent in the Late Pleistocene. We conclude that the Great Papuan Plateau is not a late and marginally occupied ‘backwater’ but rather part of a possible corridor of human movement across northern Sahul and a region that could allow us to better understand modern humans as they reached the Sahul continent.